[Neurobiology of suicidal behaviour]

The authors of this paper present a review of actual data on the neurobiological background of suicidal behaviour. The results of epidemiological studies suggest that suicidal behaviours have certain genetic background which do not depend on the presence of concomitant mental disorders. The estimated heritability rate of suicide is about 21-50%, while the heritability rate of suicidal ideation and behaviour is about 30-55%. The genes of serotonergic and noradrenergic systems, as well as the HPA axis genes, have been scrutinised in context of suicidal behaviour. Epigenetic factors are also believed to be involved in the pathogenesis of suicide. Serotonergic, noradrenergic, glutamatergic and GABAergic systems, as well as the HPA axis, are the main neural networks involved in the pathophysiology of suicide. Disorders of opioid and endocannabinoid systems can also be found in suicide victims. Pathogenesis of suicidal behaviour also contains abnormalities of cell signalising and pathology ofglial cells. Neurobiological background of akathisia and impulsivity (clinical issues closely related to the pathogenesis of suicidal behaviour) have also been presented. Most of the available trials on neurobiological background of suicidal behaviour have significant methodological weaknesses, making the results difficult to interpret. Usually they contain small samples and only single biological variables (without adjustment on environmental factors) are being analysed.